U. S. DEPARTMENT OF AGRICULTURE. 



BUREAU OF CHEMISTRY BULLETIN No. 92. 



H. W. WILEY, Chief. 



BY 



ALLERTON S. CUSHMAN, 



CJ1-IEM.ISST, r>IVISIOIX OX^ 1 TJEJSSTS. 



WASHINGTON: 



G O V K R N M K X T 1> R I N T I N (1 O F VIC E 



1905. 



